KR100687817B1 - Method for detecting welding current data by rotating of welding torch - Google Patents

Abstract

A method for detecting welding current data on rotational positions of a welding torch is provided to match an output signal outputted from an encoder of a servo motor with a welding current measured from a hole sensor in real-time when performing a rotary arc welding operation at a high speed. A method for detecting welding current data on rotational positions of a welding torch comprises: a step(S601) of providing a signal conversion part with a reference location output signal of the encoder outputted from an encoder of a servo motor drive during rotation of the welding torch; a step(S603) of converting the reference location output signal into a conversion peak signal in which a detected time point of the reference location output signal is a peak point through the signal conversion part; a step(S605) of simultaneously receiving the conversion peak signal and welding current data detected from a hole sensor for outputting a welding current according to the rotation of the welding torch; a step(S607) of recognizing a rotary position of the welding torch corresponding to the peak point of the conversion peak signal using the conversion peak signal and the welding current data that are simultaneously received; a step(S609) of reflecting an offset value to the recognized rotary position of the welding torch corresponding to the peak point to calculate actual rotary position data of the welding torch; a step(S611) of matching the calculated actual rotary position data of the welding torch with the welding current data; and a step(S613) of detecting welding current data on rotary locations of the welding torch from the matched rotary position data and welding current data.

Description

Method for detecting welding current data by rotating of welding torch}

1 is a perspective view showing a working state of a conventional high speed rotary arc welding.

Figure 2 is an exemplary view showing an output signal output from the encoder of the servo motor provided to the arc rotation sensor according to the prior art.

Figure 3 is a block diagram schematically showing a high speed rotating arc welding system using a servo motor according to an embodiment of the present invention.

Figure 4 is an exemplary view showing a rotation position data and welding current data in a graph according to a preferred embodiment of the present invention.

5a and 5b are schematic views showing matching of the converted peak signal and welding current data in the rotating arc sensor device according to the preferred embodiment of the present invention.

Figure 6 is a flow chart illustrating a procedure for detecting the welding current data for each rotation position of the welding torch in the high speed rotating arc welding system according to a preferred embodiment of the present invention.

7 is an exemplary view showing a region for each rotation position of a welding torch in which welding current data is detected according to a preferred embodiment of the present invention.

8 is an exemplary view illustrating a state in which a reference position output signal output from an encoder of a servo motor according to an exemplary embodiment of the present invention is converted into a converted peak signal.

                      <Explanation of symbols for the main parts of the drawings>

300... High speed rotary arc welding system 310... Encoder

311... Signal converter 320. Servo motor

330... Hall sensor 340... Rotary arc sensor device

341... Communication unit 343. A / D data board

345... Central processing unit 347... Motion board

350... Robot driven controller

The present invention relates to a welding current data detection method for each welding torch rotation position.

In general, high-speed rotary arc welding is used to connect members in a system for manufacturing large steel structures such as ship building, bridge construction, and the like.

The high speed rotation arc welding is a method of welding while rotating the arc at high speed as the electrode nozzle of the welding torch is mechanically rotated. The high-speed rotary arc welding can provide a flat and wide penetration shape because it distributes the arc force and arc heat uniformly in the molten pool compared to the conventional welding method, it is possible to obtain a good bead quality, high-speed welding is possible productivity It is possible to improve.

The existing high speed rotary arc welding method uses a rotary arc sensor device for automatic tracking of the welding seam during welding. The rotating arc sensor device may obtain an output signal of a welding current and a welding voltage during welding to indicate a correlation between the welding member and the welding torch.

In order to properly operate the rotary arc sensor device, it is very important to know the welding current data obtained at the upper, lower, left and right positions on the rotational trajectory of the welding torch when collecting the welding current.

In the high speed rotary arc welding according to the related art, the rotary arc sensor device performs a function of reading an encoder value output signal through a motion board when the servo motor is driven. In addition, in the case of high-speed rotating arc welding without using the encoder, the rotating arc sensor device is provided with a hardware proximity sensor to perform the function of recognizing the rotation position every rotation.

1 is a perspective view showing a working state of a conventional high-speed rotating arc welding.

Referring to FIG. 1, when the high speed rotary arc welding system according to the related art performs high speed rotary arc welding of two welding members 11 and 12, the welding torch 15 may include a servo motor 14 and a predetermined gear device ( 16, 17, in conjunction with the proximity sensor 18 and the Hall sensor to form a bead (13) on the welding line for high-speed rotation arc welding.

The welding torch 15 meshes with the rotation of the servo motor 14 to perform rotation welding in accordance with a command of a robot drive controller (not shown) that controls the operation of the high speed rotation arc welding. The servo motor 14 typically includes an encoder (not shown) of a line drive type.

Here, the encoder outputs a reference position output signal for providing reference position information of the driving servo motor 14 and a rotation position output signal for providing rotation position information, thereby providing a rotating arc sensor device for tracking seams according to the related art. Can be provided.

The proximity sensor 18 includes a function attached to the servo motor 14 to counter the number of revolutions of the gear 16 connected to the servo motor 14 and provide position information of the reference point 19.

The hall sensor (not shown) includes a function of measuring a welding current output according to the rotational position of the welding torch 15 which is controlled and operated by the robot drive controller during the high speed rotation arc welding. Here, the Hall sensor may measure the current by non-contacting a magnetic flux generated in proportion to the current through a combination of a magnetic iron core and a magnetic sensor.

Figure 2 is an exemplary view showing an output signal output from the encoder of the servo motor provided to the arc rotation sensor according to the prior art.

Referring to FIG. 2, an encoder connected to a servo motor in a high speed rotating arc welding according to the related art outputs an output signal according to a line driver method when the servo motor rotates. Here, the A slit, the B slit and the C slit are formed on one side of the rotary shaft of the servo motor or the gear interlocked with the rotary shaft.

The encoder has three optical sensors configured to output signals (A waveform, B waveform, C waveform) output from the A slit, B slit, and C slit formed in the gears of the servo motor at each rotation period T of the servo motor. 23, 25, and inverted output signals (/ A waveform, / B waveform, / C waveform) 22, 24, and 26 can be output. As shown here, the A waveform 21 and the B waveform 23 have a phase difference of 90 degrees.

The rotating arc sensor device of the high speed rotary arc welding according to the prior art is a high speed output signal of the A waveform 21, / A waveform 22, B waveform 23 and / B waveform 24 output from the encoder. It is possible to detect the rotational position of the welding torch by counting with. In addition, the rotation arc sensor device may be provided with reference position information for detecting one rotation of the servo motor through the output signal 25 of the C waveform and / C waveform output from the encoder.

However, the high-speed rotating arc welding method according to the related art is difficult to accurately input the rotation position of the welding torch in real time by counting the rotation position output signal output from the encoder at high speed during the high-speed rotating arc welding, and instructing the high speed rotating arc welding. This will continue to place a lot of load on the central processing unit.

In addition, when using the proximity sensor connected to the gear of the servo motor in the above method, there is a problem that the proximity sensor generates a wrong signal due to dust in the workplace. In addition, the proximity sensor is very important because the distance to the gear connected to the servo motor is very difficult to recognize, if too close, there are many problems in maintenance, such as fear of damage to the proximity sensor.

The present invention is to solve the above problems, an object of the present invention is a welding data detection method according to the welding position of the welding torch rotation position that can accurately detect the welding current data for each rotation position of the rotating welding torch during high-speed rotation arc welding To provide.

Another object of the present invention is to provide a welding data detection method for each welding torch rotation position capable of matching a welding current measured from a hall sensor and an output signal output from an encoder of a servo motor in real time during high speed rotating arc welding.

In order to achieve the above objects, according to an aspect of the present invention, in the method for detecting the welding current data for each rotation position of the welding torch, reference of the encoder output from the encoder of the servo motor driven when the welding torch rotates Providing a position output signal to a signal converter; converting the reference position output signal into a converted peak signal at which a point in time at which the reference position output signal is detected is a peak point through the signal converter; Simultaneously receiving the detected conversion peak signal and the welding current data detected from the hall sensor for outputting the welding current according to the rotation of the welding torch, using the simultaneously inputted conversion peak signal and the welding current data of the converted peak signal. Recognizing the rotational position of the welding torch corresponding to the peak point, the recognized blood Calculating the rotation position data of the actual welding torch by applying an offset value to the rotation position of the welding torch corresponding to the stroke point, matching the calculated welding position data with the welding current data; The method may further include detecting welding current data for each rotation position of the welding torch from the matched rotation position data and welding current data.

In an exemplary embodiment, the offset value may be a difference between an initial position on the rotational trajectory of the welding torch and an absolute reference point set as an absolute reference on the rotational trajectory of the welding torch.

Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the following description of the present invention, if it is determined that detailed descriptions of related known functions or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, the terms to be described later are terms set in consideration of functions in the present invention, and these terms may vary according to the intention or custom of the producer producing the product, and the definition of the terms should be made based on the contents throughout the present specification. .

Figure 3 is a block diagram schematically showing a high speed rotating arc welding system using a servo motor according to an embodiment of the present invention.

Referring to FIG. 3, the high speed rotating arc welding system 300 according to the present invention includes an encoder 310, a signal converter 311, a servo motor 320, a hall sensor 330, and a rotating arc sensor device 340. Robot drive controller 350 is included.

The encoder 310 outputs a reference position output signal every one revolution of the servo motor 320, and includes a function of providing the output reference position output signal to the rotating arc sensor device 340.

The signal converter 311 converts a peak signal from a point of time at which the reference position output signal is detected as a reference position output signal output from the encoder 310 to detect a rotation position of the welding torch. Converts to. Here, the reference position output signal output from the encoder 310 is the pulse interval varies depending on the speed, in the case of high-speed rotating arc welding is output at a very short interval.

The hall sensor 330 measures a welding current output according to a rotational position of the welding torch, which is controlled and operated by the robot driving controller 350 during the high speed rotation arc welding. The measured welding current may be processed into a digital signal and transmitted to the rotating arc sensor device 340 according to the present invention. In this case, since the digital signal-processed welding current data rotates the welding torch and touches two parts of the upper and lower surfaces of the welding member, two valleys and floors may appear.

The rotary arc sensor device 340 includes a communication unit 341, an A / D data board 343, a central processing unit (CPU) 345, and a motion board 347 for motion control of the welding torch.

The communication unit 341 includes a function of connecting and transmitting the central processing unit 345 and the robot driving controller 350 to each other.

The A / D data board 343 collects the conversion peak signal converted from the signal converter 311 and the welding current data measured from the hall sensor 330 at the same time in real time to form a center for matching according to the present invention. And a function for transmitting to the processing device 345.

The CPU 345 may recognize a rotation position of the welding torch corresponding to the peak point of the conversion peak signal by using the input conversion peak signal and the welding current data. In addition, the central processing unit 345 calculates the rotation position data of the actual welding torch by applying an offset value to the rotation position of the welding torch corresponding to the recognized peak point.

Here, the offset value represents a difference between an initial position on the rotational trajectory of the welding torch and a reference point set as an absolute reference on the rotational trajectory of the welding torch.

In addition, the CPU 345 performs a function of matching the calculated rotation position data of the actual welding torch and the welding current data, and detecting welding current data for each rotation position of the welding torch through the matching. do. In addition, the central processing unit 345 performs a function of instructing the robot drive controller 350 to perform a high speed arc welding along the welding line path input through the communication unit 341.

The motion board 347 includes a function of controlling the motion of the servo motor 320 driven during high speed arc welding.

The robot driving controller 350 performs a function of controlling the driving of the welding robot that performs the high-speed rotating arc welding according to the command of the central processing unit 345.

Figure 4 is an exemplary view showing a rotation position data and welding current data in a graph according to a preferred embodiment of the present invention.

Referring to FIG. 4, in the graph shown above, the rotation speed of the welding torch is 50 Hz, and the conversion peak signal 401 and the welding current data 403 for indicating 100 rotation positions in one rotation of the welding torch are shown. Sampling is performed.

The graph shows 500 data, ie data for 5 revolutions. The data number of 24 means the 24th data, and 124 means the first data to start the next rotation. That is, 24 to 123 are collected data for one revolution of the welding torch. The twenty-fourth data is a point at which a point in time at which the reference position output signal is output from the encoder of the servo motor is converted into a peak point.

In the high-speed rotating arc welding system according to the present invention, the encoder of the servo motor includes a function of transmitting a reference position output signal of the encoder output every one rotation of the servo motor to the signal converter. The signal converter which receives the reference position output signal of the encoder converts the reference position output signal of the encoder into the converted peak signal 401 by using the reference position output signal that is output every cycle of rotation of the servo motor. The signal converter may then transmit the converted peak signal 401 to the A / D data board of the rotating arc sensor device.

The hall sensor includes a function of measuring welding current data 403 according to the rotational position of the welding torch and transmitting it to the A / D data board of the rotating arc sensor device. As described above, since the welding current data 403 touches two parts of the upper surface and the lower surface of the welding member according to the rotational position of the welding torch, the welding current data 403 indicates the upper portion Up and the lower portion Dn during one cycle of rotation of the welding torch. The floor of the burn can be output.

The converted peak signal 401 and the welding current data 403 may be simultaneously input to the rotating arc sensor device according to the present invention and used to detect welding current data for each rotation position of the welding torch according to the present invention.

5A and 5B are exemplary views schematically illustrating matching of a converted peak signal and welding current data in a rotating arc sensor device according to a preferred embodiment of the present invention.

5A and 5B, as shown in FIG. 5A, a position at which the encoder's reference position output signal is output is constantly positioned at every point in the rotational track 501 of the welding torch. At this time, if the position that is constantly output on the rotational trajectory 501 of the welding torch is defined as the reference position 505, the difference between the absolute reference point 503 and the reference position 505 that occurs every rotation of the welding torch. May be defined as an offset value (507).

In this case, since the offset value 507 from the absolute reference point 503 to the reference position 505 which occurs every rotation of the welding torch is always constant, it may be calculated and input when the initial high speed rotation welding torch is assembled in advance.

In more detail, the absolute reference point 503 may divide the rotational trajectory of the welding torch into an up, down, fore, and rear. Rotating trajectories of the divided welding torches may have a position difference value of 25 based on the absolute reference point 503 0 based on 100 data numbers. That is, when the position value of the lower position of the rotation trajectory 501 is set to 0, the position value of Fore is 25, the Up is 50, and the Rear is 75 along the rotation direction. . The absolute reference point 503 is a point set as an absolute reference on the rotational trajectory 501 of the welding torch.

As illustrated in FIG. 5B, the rotation arc sensor device may reflect the offset value 507 in the converted peak signal 401 and match the welding current data 403 according to the rotation position of the welding torch.

6 is a flowchart illustrating a procedure of detecting welding current data for each rotation position of a welding torch in a high speed rotating arc welding system according to an exemplary embodiment of the present invention.

Referring to FIG. 6, first, in the high speed rotating arc welding system according to the present invention, a signal conversion unit interworking with an arc welding sensor device outputs a reference position output signal of an encoder that is output every one rotation of a servo motor driven during high speed rotating arc welding. Receive (S601).

The signal converter which receives the reference position output signal converts the reference position output signal into a converted peak signal at which a point in time when the reference position output signal is output from an encoder is used as a peak point (S603).

Thereafter, the rotating arc sensor device receives the converted peak signal from the signal converter and receives welding current data corresponding to the rotational position of the welding torch through the hall sensor (S605). As described above, the hall sensor may measure the welding current output according to the rotational position of the welding torch which is controlled and operated by the robot driving controller.

Thereafter, the rotating arc sensor device recognizes the rotation position of the welding torch corresponding to the peak point of the conversion peak signal using the simultaneously input conversion peak myth and the welding current data (S607).

In this case, the rotating arc sensor device calculates the rotation position data of the actual welding torch by reflecting a preset offset value in the rotation position of the welding torch corresponding to the recognized peak point of the converted peak signal (S609). As described above, the offset value represents a difference between an initial position on the rotational trajectory of the welding torch and an absolute reference point set as an absolute reference on the rotational trajectory of the welding torch.

Thereafter, the rotating arc sensor device matches the calculated rotational position data of the actual welding torch and the welding current data (S611). In the matching process, the converted peak signal may be shifted by the offset value to reset the rotation position of the welding torch corresponding to the welding current data.

Thereafter, the rotating arc sensor device may detect welding current data for each rotation position of the welding torch according to the present invention from the matched welding current data (S613).

7 is an exemplary view showing a region for each rotation position of a welding torch in which welding current data is detected according to an exemplary embodiment of the present invention.

Referring to FIG. 7, the rotary arc sensor device according to the present invention in the rotary orbit 700 of the welding torch includes the up 701, the down 703, the fore 705, and the rear. (Rear) The welding current data in the position area of 707 is detected.

This has a position difference of 25 each when the positional division data is 100 on the rotational track 700 of the welding torch. That is, when the position value of the down 703 on the rotary track 700 is set to 0, the fore 705 is 25 and the up 701 is 50 along the rotational direction of the welding torch. The rear 707 may have a position value of 75.

Based on this, the rotating arc sensor device matches the welding position data and the rotational position data of the actual welding torch calculated by reflecting the offset value, so that the welding current value in the up 701 region is lowered (703). The welding current value in the () region, the welding current value in the fore (705) region, and the welding current value in the rear (707) region can be obtained.

Thereafter, the rotating arc sensor device uses the welding current data detected in the rotation position region of the welding torch without using a hardware counter or a software device for preventing a time delay generated during a matching process during high-speed rotating arc welding. Arc welding of a high speed rotation according to the said welding line path | route can be performed.

8 is an exemplary diagram illustrating a state in which a reference position output signal output from an encoder of a servo motor according to an exemplary embodiment of the present invention is converted into a converted peak signal.

Referring to FIG. 8, the graph shown shows a reference position output signal (phase C) 25 and a conversion peak signal 401 output from an encoder of a servo motor during high speed rotation arc welding according to the present invention.

As described above, the signal converting unit interlocked with the rotating arc sensor device according to the present invention receives the reference position output signal 25 output from the encoder to detect the rotation position of the welding torch. Can be converted into a converted peak signal 401, which is expressed as a peak point.

The embodiments of the present invention have been described above with reference to the accompanying drawings. However, it is to be noted that the present invention is not limited only to the above-described embodiments, and that various modifications and changes can be made by those skilled in the art within the spirit and spirit of the appended claims as necessary.

According to the present invention, it is possible to provide a welding data detection method for each welding torch rotation position that can accurately detect welding current data for each rotation position of a rotating welding torch during high speed rotation arc welding.

According to the present invention, it is possible to provide a welding data detection method for each welding torch rotation position capable of matching an output signal output from an encoder of a servo motor and a welding current measured from a hall sensor in real time during high speed rotation arc welding.

Claims (2)

In the method for detecting welding current data for each rotation position of the welding torch, Providing a reference position output signal of an encoder output from an encoder of a servo motor driven when the welding torch is rotated, to a signal converter; Converting the reference position output signal into a converted peak signal at which the reference point output signal is detected as a peak point through the signal converter; Receiving welding current data detected from a hall sensor for outputting a welding current according to the converted converted peak signal and the welding torch; Recognizing a rotation position of a welding torch corresponding to a peak point of the conversion peak signal using the simultaneously input conversion peak signal and the welding current data; Calculating rotation position data of the actual welding torch by applying an offset value to the rotation position of the welding torch corresponding to the recognized peak point; Matching the calculated rotational position data of the actual welding torch with the welding current data; And Detecting welding current data for each rotation position of the welding torch from the matched rotation position data and welding current data. Welding current data detection method for each welding torch rotation position, characterized in that. The method of claim 1, The offset value is a difference between an initial position on the rotational trajectory of the welding torch and an absolute reference point set as an absolute reference on the rotational trajectory of the welding torch. Welding current data detection method for each welding torch rotation position, characterized in that.

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